[show abstract][hide abstract] ABSTRACT: The bioavailability of metals, which are known as important contact allergens, is decisive for the development and the maintenance of contact dermatitis. The aim of this study was to evaluate the percutaneous penetration of metal powders of cobalt (Co), nickel (Ni) and chromium (Cr) and the effect of skin lesions on skin absorption. In vitro permeation experiments were performed using the Franz diffusion cells with intact and damaged human skin. Physiological solution was used as receiving phase and metal powders (Co, Ni and Cr) dispersed in synthetic sweat at pH 4.5 were applied as donor phase to the outer surface of the skin for 24h. The amount of each metal permeating the skin was analysed by electro-thermal atomic absorption spectroscopy (ETAAS). Donor solution analysis demonstrated that metals were present as ions. Measurements of metals skin content were also exploited. Median Co and Ni concentrations found in the receiving phase were significantly higher when Co and Ni powders were applied on the abraded skin than after application on the intact skin (3566 and 2631ngcm(-2) vs. 8.4 and 31ngcm(-2), respectively). No significant difference was found in Cr permeation through intact and damaged skin. The measurement of metals skin content showed that Co, Ni and Cr concentrations were significantly higher in the damaged skin than in the intact skin. Co and Ni ions concentrations increased significantly when the donor solutions were applied on the damaged skin, while Cr ions concentrations did not increase. This study demonstrated that Co and Ni powders can permeate through damaged skin more easily than Cr powder, which has probably a stronger skin proteins binding capacity. Therefore, our results suggest that is necessary to prevent skin contamination when using toxic substances because a small injury to the skin barrier can significantly increase skin absorption.
Toxicology in Vitro 07/2009; 23(4):574-9. · 2.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: There is a growing interest on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin. This study aims at evaluating in vitro skin penetration of silver nanoparticles. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 microg/cm2 of silver nanoparticles coated with polyvinylpirrolidone dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24h. The receptor fluid measurements were performed by electro thermal atomic absorption spectroscopy (ETAAS). Human skin penetration was also determined by using transmission electron microscope (TEM) to verify the location of silver nanoparticles in exposed membranes. Median silver concentrations of 0.46 ng cm(-2) (range <LOD-2.23) and 2.32 ng cm(-2) (range 0.43-11.6) were found in the receiving solutions of cells where the nanoparticles solution was applied on intact skin (eight cells) and on damaged skin (eight cells), respectively. Twenty-four hours silver flux permeation in damaged skin was 0.62+/-0.2 ng cm(-2) with a lag time <1h. Our experimental data showed that silver nanoparticles absorption through intact and damaged skin was very low but detectable, and that in case of damaged skin it was possible an increasing permeation of silver applied as nanoparticles. Moreover, silver nanoparticles could be detected in the stratum corneum and the outermost surface of the epidermis by electron microscopy. We demonstrated for the first time that silver applied as nanoparticles coated with polyvinylpirrolidone is able to permeate the damaged skin in an in vitro diffusion cell system.
[show abstract][hide abstract] ABSTRACT: The present study tried to investigate, using a synthetic sweat at pH 4.5, whether metallic chromium can pass through the skin (in vitro) and the effect of rapid skin decontamination with a common detergent. A suspension of chromium powder in synthetic sweat at pH 4.5 was prepared and shaken with a stirring plate at room temperature for 30 min. Human skin membranes were set up in Franz-diffusion cells and 1 ml of the freshly made suspension was applied to the outer surface of the skin for 24h. The tests were performed without and with decontamination using the cleanser 30 min after the start of exposure. The appearance of metal ions in the aqueous receptor phase was quantified by Electro Thermal Atomic Absorption Spectroscopy (ETAAS) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Speciation analysis and measurements of chromium skin content were also performed. Chromium skin permeation was demonstrated in in vitro experiments using the Franz cell system, giving a permeation flux of 0.84+/-0.25 ng cm(-2)h(-1) and a lag time of 1.1+/-0.7h. The cleaning procedure stop Cr permeation but its concentration into the skin significantly increased (Mann-Whitney U test P<0.03). The results revealed that chromium applied as powder can pass through the skin and that decontamination, done after 30 min of exposure, prevent Cr skin permeation but increase Cr content into the skin.
Toxicology in Vitro 06/2008; 22(6):1562-7. · 2.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the relation between manipulative dexterity and vibration exposure, ergonomic risk factors, and upper limb disorders in a group of workers exposed to hand-transmitted vibration (HTV).
Manipulative dexterity was investigated on 115 HTV workers (82 forestry workers and 33 stone workers) and 64 control men over 1-year follow-up period. The Purdue pegboard method was used to test manipulative dexterity which was scored for the dominant hand, non-dominant hand, and both hands. Information about individual, work and health history was obtained by means of a standardised questionnaire. Vibration exposure was assessed in terms of tool vibration magnitudes, daily and total exposure duration, and cumulative vibration dose.
On the cross-sectional investigation, Purdue pegboard scores were significantly lower in the HTV workers than in the controls (0.001 < P < 0.05). Over 1-year follow-up period, Purdue pegboard scores were found to be inversely related to age, smoking and use of vibratory tools (0.001 < P < 0.05). Moreover, deterioration of some measures of manipulative dexterity was significantly associated with sensorineural and vascular symptoms in the fingers of the HTV workers. Random-intercept linear regression analysis showed that Purdue pegboard scores decreased with the increase of vibration exposure. The reduction of assembly score (i.e. number of pins, collars, and washers assembled in a 60-s period) was significantly associated with the increase in vibration exposure and ergonomic stress (neck-upper arm posture, hand-intensive work, and total ergonomic score). Purdue pegboard scores tended to improve over the follow-up period in both the controls and the HTV workers, suggesting a possible learning effect over time.
The findings of this longitudinal study suggest an association between deterioration of manipulative dexterity and neurovascular symptoms in the fingers of HTV workers. There was evidence for a significant relation between loss of precise manipulation and exposures to hand-transmitted vibration and ergonomic risk factors.
International Archives of Occupational and Environmental Health 05/2008; 81(5):545-51. · 2.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate prospectively the relation between vibration-induced white finger (VWF), exposure to hand-transmitted vibration (HTV) and the cold response of digital arteries in users of vibrating tools.
Two-hundred and sixteen HTV workers and 133 control men of the same companies underwent initially a medical examination and a standardised cold test with measurement of the change in finger systolic blood pressure (FSBP) after finger cooling from 30 to 10 degrees C. They were re-examined 1 year later. Tool vibration magnitudes were expressed as frequency-weighted and unweighted r.m.s. accelerations. From the vibration magnitudes and exposure durations, alternative measures of cumulative vibration dose were calculated for each HTV worker, according to the expression: Sigma(alpha)(m)(i)(t)(i), where a ( i ) is the acceleration magnitude on tool i, t ( i ) is the lifetime exposure duration for tool i, and m = 0, 1, 2 or 4.
Among the HTV workers, the initial prevalence and the 1-year incidence of VWF were 18.1 and 1.7%, respectively. At the first examination, the HTV workers with moderate or severe score for VWF showed a significantly increased cold reaction in the fingers when compared with the controls and the HTV workers with no vascular symptoms. At the follow-up, the controls, the asymptomatic HTV workers, and the prevalent cases of VWF did not show significant changes in the cold response of digital arteries. A deterioration of cold-induced digital vasoconstriction was found in the incident cases of VWF. In the HTV workers, vibration doses with high powers of acceleration (i.e., Sigma(alpha)(m)(i)(t)(i) with m > 1) were major predictors of the vasoconstrictor response to cold at the follow-up examination.
The measurement of FSBP after local cooling may be a helpful objective test to monitor prospectively the change in vibration-induced vascular symptoms. The findings of this longitudinal study suggest a dose-effect relationship between cold-induced digital arterial hyperresponsiveness over time and measures of cumulative vibration exposure. In the controls, the cold response of the digital arteries was stable over 1-year follow-up period.
International Archives of Occupational and Environmental Health 05/2008; 81(5):613-23. · 2.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: To assess the usefulness of color charts for the diagnosis of finger whiteness in vibration-exposed workers.
A group of 146 forestry and stone workers exposed to hand-transmitted vibration (HTV) were examined twice over 1 year follow up period. The anamnestic diagnosis of finger whiteness was made on the basis of (a) a medical history alone, and (b) the administration color charts which showed changes in the skin color of fingers and hands. The cold response of digital arteries was assessed by measuring the change in finger systolic blood pressure (FSBP) after local cooling from 30 to 10 degrees C (FSBP%(10 degrees )).
Assuming the administration of color charts as the gold standard, the sensitivity and specificity of the medical history alone to diagnose finger whiteness was 88.2 and 93.8%, respectively, at the initial cross-sectional study and 94.4 and 97.7% at the end of the follow-up. Random-intercept linear regression analysis of follow up data showed that after adjustment for several covariates, FSBP%(10 degrees )was significantly associated with finger whiteness assessed by either medical history alone (P < 0.005) or the color charts (P < 0.001). However, a statistical measure of overall fit of regression models (Bayesian Information Criterion) suggested that the color chart method performed better than medical history alone for the prediction of the cold response of digital arteries.
The administration of color charts seems to reduce the proportion of false positive responses for finger whiteness in a population of vibration-exposed workers. The color chart method was a more significant predictor of digital arterial hyperresponsiveness to cold than medical history alone. These findings suggest that the use of color charts in clinical and epidemiological studies may be of help to assist in the diagnosis of finger whiteness in vibration-exposed workers.
International Archives of Occupational and Environmental Health 04/2008; 81(5):633-8. · 2.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study investigated the relation between salivary endothelin, vibration exposure, and vascular disorders in a group of forestry workers.
Altogether 54 forestry workers and 52 controls underwent a medical examination and a cold test with measurement of the percentage of change in finger systolic blood pressure after finger cooling from 30 degrees C to 10 degrees C (FSBP% (10 degrees)). Salivary endothelin concentration (ET(1-21), in fmol/ml) was measured by a commercially available enzyme-linked immunosorbent assay before and after the cold challenge. The anamnestic diagnosis of vibration-induced white finger (VWF), assisted by color charts, was based on the Stockholm Workshop criteria.
Six forestry workers (11%) and one control (2%) reported white fingers. Before the cold challenge, the salivary ET(1-21) concentration was significantly greater in the VWF workers than in the controls (P=0.036). The cold response of digital arteries was stronger in the VWF workers than in the controls (P<0.001) and the asymptomatic forestry workers (P=0.008). After the cold test, there was a small, not significant, increase in the salivary ET(1-21) concentration in both the controls and the forestry workers. For the latter, the salivary ET(1-21) concentration was significantly associated with both daily and total operating time with vibrating tools. A significant inverse relation between FSBP% (10 degrees )and the salivary ET(1-21) concentration was observed for the forestry workers with an abnormal cold response in their digital arteries.
This study showed an association between salivary ET(1-21) concentration, daily and cumulative vibration exposure, and vascular disorders in the fingers of professional forestry workers. Since ET(1-21) can induce powerful and long-lasting constriction of human vessels, these findings suggest a possible role of this vasopeptide in the pathogenesis of VWF.
Scandinavian journal of work, environment & health 04/2008; 34(2):133-41. · 3.78 Impact Factor
[show abstract][hide abstract] ABSTRACT: The European Directive 2002/44/EC and the Italian Decree 187/2005 establish the minimum health and safety requirements regarding the exposure of workers to the risks arising from mechanical vibration. Excessive exposure to hand-arm vibration from powered processes or tools can cause disorders in the vascular, neurological and musculoskeletal systems of the upper limbs. Long-term occupational exposure to intense whole-body vibration is associated with an increased risk for disorders of the lumbar spine and the connected nervous system. The prevention of injuries or disorders caused by mechanical vibration at the workplace requires the implementation of administrative, technical and medical procedures. The role of the occupational health physician in the implementation of the health surveillance of vibration-exposed workers is discussed in the light of the requirements established by the European and Italian regulations. The health surveillance of vibration-exposed workers consists of pre-employment medical screening and subsequent clinical examinations at regular intervals. The aims of health surveillance are to make the worker aware of the hazards connected with exposure to mechanical vibration, to obtain baseline health data for comparison with the findings of subsequent periodical health examinations, to verify the presence of pathological conditions which may increase the risk of adverse health effects due to vibration exposure, to make a diagnosis of occupational or work-related disease, and to check the long-term effectiveness of preventive measures.
Giornale italiano di medicina del lavoro ed ergonomia 01/2006; 28(3):241-4.
[show abstract][hide abstract] ABSTRACT: We re-investigated 13 workers 6 years (SD 2) after the first diagnosis of asthma or rhinitis caused by latex, to update the exposure to latex, the eventual symptoms, respiratory function (spirometry and metacholine PD20 FEV1), skin prick test to common allergens and latex, RAST to latex, total IgE levels and eosinophils count in the blood. At the follow up, all the workers stopped wearing powdered latex gloves, but for 10 an indirect exposure to latex was still possible. All cases referred improvement of respiratory symptoms at work, but 7 workers occasionally complained of mild symptoms. No statistically significant variations of respiratory function test and of the immunological parameters were found. The workers with persistent respiratory symptoms at work had a longer duration of symptoms before the diagnosis (p = 0.02), if compared with workers without symptoms.
Giornale italiano di medicina del lavoro ed ergonomia 01/2003; 25 Suppl(3):235-6.
[show abstract][hide abstract] ABSTRACT: The dermal risk assessment requires simplified methodologies to understand the role played by the skin. The conceptual models proposed to this aim are founded on theoretical assumptions and experimental data, but their use in occupational settings shows many difficulties. For this end we have drawn up a check-list that includes six sessions and allows to obtain a preliminary dermal exposure evaluation subdivided on hazard bands.
Giornale italiano di medicina del lavoro ed ergonomia 01/2003; 25(3):350-2.
[show abstract][hide abstract] ABSTRACT: Anti-smoking counseling is often part of healthcare protocols for workers with past asbestos exposure; nevertheless, data is lacking about the results.
To evaluate smoking habits and the effects of anti-smoking counseling in a group of workers with past asbestos exposure.
Smoking was assessed in 671 subjects who voluntarily attended a health surveillance protocol. Fagerstrom's and Richmond's tests were used in order to estimate smokers' addiction and their potential will to quit. Besides anti-smoking counseling, smokers were also offered a formal cessation programme.
The mean age of the 671 subjects was 66 (DS = 7,9) years. The population consisted of 87 (13%) current smokers, 372 (55%) ex-smokers and 212 (32%) non smokers. According to Fagerstrom's test results, only 10% of the smokers presented a strong/very strong addiction, while Richmond's test results showed that 50% of the smokers had a strong/very strong will to quit. Only one smoker decided to join a cessation programme.
The results of the study could present a bias, because volunteer-based protocols may promote the participation of self-motivated and health-sensitive subjects. This could be one of the reasons for the low prevalence of current smokers and high prevalence of ex-smokers. Anti-smoking counseling did not produce satisfactory effects because smokers were resistant to quitting smoking. Identification of anti-smoking counseling weak points may improve efficacy in health prevention controls made on subjects with past asbestos exposure.
La Medicina del lavoro 103(6):449-58. · 0.38 Impact Factor
[show abstract][hide abstract] ABSTRACT: There is a growing interest in the debate on nanoparticle safety for topical use. The benefits of nanoparticles have been shown in several scientific fields, but little is known about their potential to penetrate the skin lies. This study aims at evaluating in vitro silver nanoparticles skin penetration. Experiments were performed using the Franz diffusion cell method with intact and damaged human skin. Physiological solution was used as receiving phase and 70 microg/cm2 of silver nanoparticles dispersed in synthetic sweat were applied as donor phase to the outer surface of the skin for 24h. The receptor fluid measurements were performed by Electro Thermal Atomic Absorption Spectroscopy (ETAAS). Silver concentration of 0.2 microg/L was found in the receiving solutions of two cells, in which damaged skin membranes were set up. In the other tests, we obtained a silver concentration below the limit of detection in the receiving cells. Our experimental data show that silver nanoparticles permeation through intact and damaged skin is negligible. These findings are consistent with previously published results. Further researches are necessary to explore skin absorption of silver nanoparticles.
Giornale italiano di medicina del lavoro ed ergonomia 29(3 Suppl):451-2.